Base on balls

A base on balls (BB), better known as a walk,
occurs in baseball when a batter receives four pitches during a plate appearance that the umpire calls balls, and is in turn awarded first base without the possibility of being called out. The base on balls is defined in Section 2.00 of baseball’s Official Rules, and further detail is given in 6.08(a). Despite being known as a “walk”, it is considered a faux pas for a professional player to actually walk to first base; the batter-runner and any advancing runners normally jog on such a play.